I have been using this for years, it's easy to use & has many options available as far customization goes! It makes sending invoices out fast without having much hassle or issues with my clients (they are always happy!).
There isn't anything that i dislike about orange mailers in general but maybe some of their features could be improved upon such as customer support- sometimes they don’t get back until after hours/days later when you need help immediately!! If your looking into an invoice software option then make sure its something reliable like OMA - not going anywhere quick so ensure longevity is key here. We send thousands each month through our platform which we can track via email reports etc., everything works well together within one system allowing us efficiency across all platforms.- Invoice creation / tracking emails sent by client management team members easily.